Implement code review suggestions

* Tweak mutations and update unit tests

ee/app/assets/javascripts/security_configuration/modules/configuration/mutations.js

@@ -6,12 +6,15 @@ export default {
   },
   [types.REQUEST_SECURITY_CONFIGURATION](state) {
     state.isLoading = true;
+    state.errorLoading = false;
   },
   [types.RECEIVE_SECURITY_CONFIGURATION_SUCCESS](state, payload) {
     state.isLoading = false;
+    state.errorLoading = false;
     state.configuration = payload;
   },
   [types.RECEIVE_SECURITY_CONFIGURATION_ERROR](state) {
     state.isLoading = false;
+    state.errorLoading = true;
   },
 };

ee/spec/frontend/security_configuration/modules/configuration/mutation_spec.js

@@ -21,6 +21,7 @@ describe('security configuration module mutations', () => {
     it('should set the isLoading to true', () => {
       mutations[types.REQUEST_SECURITY_CONFIGURATION](state);
       expect(state.isLoading).toBe(true);
+      expect(state.errorLoading).toBe(false);
     });
   });
 
@@ -29,6 +30,7 @@ describe('security configuration module mutations', () => {
       const configuration = {};
       mutations[types.RECEIVE_SECURITY_CONFIGURATION_SUCCESS](state, configuration);
       expect(state.isLoading).toBe(false);
+      expect(state.errorLoading).toBe(false);
       expect(state.configuration).toBe(configuration);
     });
   });
@@ -37,6 +39,7 @@ describe('security configuration module mutations', () => {
     it('should set the isLoading to false', () => {
       mutations[types.RECEIVE_SECURITY_CONFIGURATION_ERROR](state);
       expect(state.isLoading).toBe(false);
+      expect(state.errorLoading).toBe(true);
     });
   });
 });